Date: Thu, 03 May 2007 15:28:01 -0500
From: Doc Shipley <doc at mdrconsult.com>
Subject: Re: Unix disk copy using dd
Sridhar Ayengar wrote:
M H Stein wrote:
Assuming you have a third disk or a spare
partition on the larger drive,
can't you tar the small disk > to a file there and then untar to the
final
disk/partition?
You're assuming that the small disk the data is coming from contains a
file system.
And, if it does, it's more efficient to use a pipe instead of a tarfile.
Peace... Sridhar
--------------
Mike:
I did indeed assume a filesystem; under what circumstances would a Unix
hard disk not have a file system?
And what do you mean specifically by "use a pipe"? Example?
If you don't need an archive copy couldn't you just copy the boot file and
cp the root?
My experience with Unix is pretty limited, but this is how I archive and
copy systems with Cromix; the tar file is copied to a PC and zipped, and
unzipped and restored if/when needed. If there's a more efficient way, I'm
definitely interested.
=========
Doc wrote:
Enering pedant mode, even if the source disk has a
filesystem, tar
can't grab boot blocks, partition tables, extended attributes,
etc. And
various tar implementations have other nasty little warts.
-------------
Mike:
Granted, you'd have to create the boot block on the new drive, but I
thought the whole point was to _not_ copy the partition table since you're
moving to a larger drive? In my Cromix experience at least, which
attributes are retained seems to be a function of the version of tar
(or ftar) and the options selected.
=======
dd is about the dumbest** command on the planet, which
is why I love it.
Doc
-------------
Mike:
Ditto, but how would you use it in this case?
m